1. Shawn Lipowski
  2. BrainBugz

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BrainBugz / docs / bb_sd_target.htm

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    <td bgcolor="#003366"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="inst"></a>&nbsp;steering 
      desires - target desires</font></td>
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<p>- target desires need targets to work, this can be any type of geometry (except 
  subdivision surfaces) <br>
  - connect geometry to the steering desire node using the Connection Editor you 
  can call with the buttons in the Attribute Editor<br>
  - note if you choose to use field of view, this will be only used for bug &lt;-&gt; 
  assigned target point (does not need to be the whole geometry!) relations</p>
<p><img src="images/sdTargetAE.gif" width="364" height="438" border="1"></p>

  <table width="92%" border="1" cellspacing="0" cellpadding="0" bordercolor="#666666">
    <tr valign="top" bgcolor="#FFFFCC"> 
      <td colspan="3"><b>Target Desire Attributes</b></td>
    </tr>
    <tr valign="top"> 
      <td width="14%"><b>Target Type</b></td>
      <td width="7%">enum</td>
      <td width="79%" valign="top"> &quot;point&quot;, &quot;curve&quot;, &quot;surface&quot;, 
        &quot;mesh&quot;<br>
        - items only active if matching geometry is connected</td>
    </tr>
    <tr valign="top"> 
      <td width="14%"><b>Sub Targets</b></td>
      <td width="7%">enum</td>
      <td width="79%" valign="top"> 
        <p>&quot;uniform&quot;<br>
          - targets are placed equidistant on curve or surface<br>
          - if you experience that targets are not uniformly placed on the specific 
          geometry, then try to 'Rebuild Curve / Surface' and be sure to check 
          radiobutton 'uniform'<br>
          - if 'Input Selection' is 'All Connected' targets will be distributed 
          on connected curves / surfaces with respect to the different curve lengths 
          / surface areas</p>
        <p>&quot;knots / vertices&quot;<br>
          - all knots / vertices of curve / surface / mesh will be used as targets</p>
      </td>
    </tr>
    <tr valign="top"> 
      <td width="14%" height="105"><b>Input Selection</b></td>
      <td width="7%" height="105">enum</td>
      <td width="79%" valign="top" height="105">&quot;index&quot;<br>
        - only one geometry (defined by &quot;input index&quot;) will be used 
        for computation<br>
        <br>
        &quot;all connected&quot;<br>
        - use all geometry connected to steering desire for computation</td>
    </tr>
    <tr valign="top"> 
      <td width="14%" height="35"><b>Input Index</b></td>
      <td width="7%" height="35">short</td>
      <td width="79%" valign="top" height="35">- specifies which input geometry 
        is to be used, provide the index at which the desired geometry is attached 
        to the respective array attribute </td>
    </tr>
    <tr valign="top"> 
      <td width="14%" height="33"><b>Tolerance</b></td>
      <td width="7%" height="33">double</td>
      <td width="79%" valign="top" height="33">- the amount of error (epsilon 
        value) in the calculation, this is used when calculating points / distances 
        to nurbs curves and surfaces</td>
    </tr>
  </table>
  
<br>
&nbsp; 
<table width="96%" border="0">
    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTsee"></a>&nbsp;seek</font></td>
    </tr>
  </table>
<p>- seek desire causes the bug to align its orientation towards the specified 
  target<br>
  - if a bug continues to seek, it will pass through the target, then turn back 
  to seek it again <br>
  - produces zero result if 'Desired Speed'=0 or target not in field of view</p>
<p><img src="images/sd_pSeek.gif" width="145" height="68" border="1"><br>
  <br>
  <img src="images/sd_cSeek.gif" width="245" height="179" border="1"></p>
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    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTmot"></a>&nbsp;moth 
        seek</font></td>
    </tr>
  </table>

<p>- moth seek desire is the same as seek, except that the bug is moving in orbital 
  paths around the target, much like a moth buzzing around a light bulb <br>
  - produces zero result if 'Desired Speed'=0 or target not in field of view</p>
<p><img src="images/sd_pMothSeek.gif" width="199" height="122" border="1"></p>
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      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTarr"></a>&nbsp;arrival</font></td>
    </tr>
  </table>

<p>- arrival is identical to seek behaviour when the bug is far away from the 
  target, but if the target is in a predefined distance (Stopping Radius), the 
  bug will try to slow down and eventually stop at the target <br>
  - produces zero result if 'Desired Speed'=0 or target not in field of view</p>
<p><img src="images/sd_pArrival.gif" width="221" height="106" border="1"></p>

  <table width="93%" border="1" cellspacing="0" cellpadding="0" bordercolor="#666666">
    <tr valign="top" bgcolor="#FFFFCC"> 
      <td colspan="3"><b>Arrival Attributes</b></td>
    </tr>
    <tr valign="top"> 
      <td width="16%"><b>Stopping Range</b></td>
      <td width="7%">double</td>
      <td width="77%">- active if steering desire is arrival<br>
        - predefined distance at which the bug will try to slow down and stop 
        at the target </td>
    </tr>
  </table>
<br>
&nbsp; 
<table width="96%" border="0">
    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTpur"></a>&nbsp;pursuit</font></td>
    </tr>
  </table>

<p>- pursuit is identical to seek behaviour except the bug tries to predict where 
  its target is moving and tries to intercept the targtes path<br>
  - this will only produce visible result, if the target is moving<br>
  &nbsp; <br>
  <img src="images/sd_pursuit.gif" width="235" height="135" border="1"> <br>
</p>

  <table width="96%" border="0">
    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTsha"></a>&nbsp;shadow</font></td>
    </tr>
  </table>
<p>- shadow is identical to seek behaviour when the bug is far away from the target, 
  but if the target is in a predefined distance (Shadow Range), the bug will try 
  mimic the movement of the target<br>
  - produces zero result if 'Desired Speed'=0 or target not in field of view</p>
<p><img src="images/sd_shadow.gif" width="215" height="203" border="1"></p>
<table width="93%" border="1" cellspacing="0" cellpadding="0" bordercolor="#666666">
  <tr valign="top" bgcolor="#FFFFCC"> 
    <td colspan="3"><b>Shadow Attributes</b></td>
  </tr>
  <tr valign="top"> 
    <td width="16%" height="38"><b>Shadow Range</b></td>
    <td width="7%" height="38">double</td>
    <td width="77%" height="38">- active if steering desire is shadow<br>
      - predefined distance at which the bug will try to mimic the movement of 
      the target</td>
  </tr>
</table>
<p>&nbsp;</p>

  <table width="96%" border="0">
    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTfol"></a>&nbsp;follow</font></td>
    </tr>
  </table>
<p>- bug estimates its future position on its current heading, then seeks the 
  closest point on the curve / surface / mesh to this future position<br>
  - 'Probe Length' serves as scaling factor for the current velocity to calculate 
  the future position<br>
  - bugs do (currently) follow the curve in no predefined direction<b><br>
  </b>- field of view is currently not available with this steering desire<br>
  - produces zero result if bug inside space defined by 'Target Radius'</p>
<p><img src="images/sd_CurveFollowing.gif" width="233" height="181" border="1"></p>

  
<table width="93%" border="1" cellspacing="0" cellpadding="0" bordercolor="#666666">
  <tr valign="top" bgcolor="#FFFFCC"> 
    <td colspan="3"><b>Follow Attributes</b></td>
  </tr>
  <tr valign="top"> 
    <td width="14%"><b>Target Radius</b></td>
    <td width="8%">double</td>
    <td width="78%">- active if steering desire is following<br>
      - defines area around curve / surface in which a bug thinks it is following 
      the path and does not change its direction</td>
  </tr>
  <tr valign="top"> 
    <td width="14%"><b>Probe Length</b></td>
    <td width="8%">double</td>
    <td width="78%">- scaling factor for the current velocity to calculate the 
      future position</td>
  </tr>
  <tr valign="top"> 
    <td width="14%"><b>Tolerance</b></td>
    <td width="8%">double</td>
    <td width="78%">- defines the maximum error used in the calculation, the bigger 
      the value, the faster the computation</td>
  </tr>
</table>
<br>
&nbsp; 
<table width="96%" border="0">
    <tr> 
      <td bgcolor="#005BB7"><font face="Arial, Helvetica, sans-serif" size="4" color="#FFFFFF"><a name="sdTobs"></a>&nbsp;obstacle 
        avoidance </font></td>
    </tr>
  </table>

<p>- obstacle avoidance prevents the bugs from bumping into obstacles (which can 
  be any mesh or nurbs surface)<br>
  - every bug has got a probe of a specified length attached at its front, if 
  this probe touches one of the specified obstacles, then the bug will try to 
  steer away from this predicted collision point <br>
  - though you can use nurbsSurfaces as obstacles, it is recommended to use meshes 
  as the collision point calculation can be performed much faster with this type 
  of geometry</p>
<p><img src="images/sd_obstacleAvoidance.gif" width="250" height="139" border="1"></p>
<table width="93%" border="1" cellspacing="0" cellpadding="0" bordercolor="#666666">
  <tr valign="top" bgcolor="#FFFFCC"> 
    <td colspan="3"><b>Follow Attributes</b></td>
  </tr>
  <tr valign="top"> 
    <td width="15%"><b>Probe Length</b></td>
    <td width="8%">double</td>
    <td width="77%">- probe length to check for obstacles</td>
  </tr>
  <tr valign="top">
    <td width="15%"><b>Tolerance</b></td>
    <td width="8%">double</td>
    <td width="77%">- defines the maximum error used in the calculation, the bigger 
      the value, the faster the computation</td>
  </tr>
</table>

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